CN1308184A

CN1308184A - Cylinder head of internal combustion engine

Info

Publication number: CN1308184A
Application number: CN01111636A
Authority: CN
Inventors: 小松田卓; 青木薰; 高桥伸一; 高木卓也; 中村弘; 山崎勉
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2000-02-10
Filing date: 2001-02-09
Publication date: 2001-08-15
Anticipated expiration: 2021-02-09
Also published as: US20010013326A1; BR0100477A; JP3824832B2; DE60127478D1; CA2335261C; EP1124052B1; TW475972B; US6622686B2; EP1124052A3; CN1170059C; EP1124052A2; DE60127478T2; JP2001221099A; CA2335261A1

Abstract

In a cylinder head 1 of an internal combustion engine, communicating passageways 17, 18, 17', 18' for coolant are provided between combustion chambers 3 and pass-through holes 21 to 28 at positions which overlap straight lines L1, L2 connecting centers C2, C3 of the exhaust port openings 6a, 7a with centers C5 to C8 of the pass-through holes 25 to 28 and straight lines L3, L4 connecting centers C9, C10 of the intake port openings 4a, 5a with centers C11 to c14 of the pass-through holes 21 to 24 when a mating surface 2 of the cylinder head 1 with the cylinder block is viewed from the bottom. When peripheries of the exhaust port openings 6a, 7a and intake port openings 4a, 5a thermally expand, the suppression of thermal expansion by the bolts at fastening portions is alleviated by the communicating passageways 17, 18, 17', 18'.

Description

The cylinder head of internal-combustion engine

The present invention relates to a kind of cylinder head of internal-combustion engine, more particularly relate to a kind of air cylinder head structure, have the cylinder head of making on it and be fixed to the through hole that the fastening piece on the cylinder body passes through, to avoid causing the suction port distortion, perhaps eliminate the relief opening distortion that causes owing to the thermal expansion around the relief opening by the thermal expansion around the suction port.Suction port is wherein opened and/or is closed by intake valve control, and relief opening is opened and/or closed by exhaust valve control.

In internal-combustion engine, be furnished with suction port and the relief opening opening and/or close by the control of suction valve and outlet valve on the cylinder head respectively, temperature raises the cylinder head part owing to be exposed in the combustion gas, and then makes the temperature around suction port and the relief opening also raise.On the other hand, around the firing chamber, the radial outside of suction port and relief opening on cylinder head is provided with the through hole that a plurality of clamping bolts pass through, and tightens by the clamping bolt that will be inserted in the clamping bolt through hole, just cylinder head can be fixed on the cylinder body.

Thereby the suction port and the relief opening peripheral part that are subjected to the high temperature heating are uniform to the thermal expansion of peripheral direction basically.But as shown in Figure 7, fastening part is arranged on suction port a and the relief opening b radial outside direction, and these fastening parts are tightened by the clamping bolt that is inserted among the through hole c.Therefore, when from the fitting surface of cylinder body and cylinder head bottom, fastening part will retrain thermal expansion, especially suction port a on the line d direction that connects suction port a or relief opening b center and through hole c center or relief opening b along straight line d direction and and the neighbouring part of straight line d coincidence on thermal expansion.Thus, just can not evenly expand around suction port a or the relief opening b, thereby will make the suction port a or the relief opening b that are generally circular become not for circular, and when such situation takes place, regional f around suction port a or relief opening b and and the neighbouring part that overlaps of straight line e will form thermal stress and concentrate, its cathetus e intersects by suction port a or relief opening b center and with straight line d.Thereby, will in regional f, produce creep strain by thermal stress, this will make suction port a or relief opening b become more not for circular.What attention reference character g represented is the logical perforation of spark plug that faces toward the firing chamber.

When such as mentioned above distortion takes place in suction port or relief opening, the sealability of suction valve or outlet valve will worsen, and will allow unburned combustion-gas mixture from letting out between suction valve and the suction port or between outlet valve and relief opening like this in the compression stroke process.And when unburned combustion-gas mixture after leak between suction valve and the suction port, because fuel can be back to suction port, thereby can have a strong impact on the control accuracy of combustion gas ratio, and when unburned combustion-gas mixture after leak between outlet valve and the relief opening, HC content in the waste gas will raise, thereby makes gas exhausting property worsen.

Therefore, in order to prevent that suction valve or outlet valve are owing to the creep of the thermal expansion distortion of suction port or relief opening or suction port or relief opening peripheral part causes close divinatory symbol performance to reduce, usually to do certain restriction to the maximum combustion temperature of internal-combustion engine, or the volume of coolant jacket on the increase cylinder head, to improve cooling performance, eliminate the distortion of suction port or relief opening thus, thereby guarantee the close divinatory symbol performance of suction valve or outlet valve.

Yet, the output of the maximum combustion temperature meeting limiting engine of limit engine, for example in the situation of motor car engine, when the maximum combustion temperature of internal-combustion engine was restricted, the service behaviour of the automobile that matches will be restricted.Therefore, because the maximum combustion temperature of limit engine can cause the service behaviour of the equipment that matches to be restricted, therefore wish this is improved.In addition, for example the measure that improves cooling performance by the method that increases cooling jacket volume on the cylinder head can strengthen cooling mechanism, causes cylinder head to become big, thereby has limited the layout degrees of freedom of internal-combustion engine.

Proposed the present invention based on these situations, its purpose is to improve with a kind of simple structure the power output of motor, and just can guarantee the sealability of suction valve or outlet valve without the intensifying cylinder lid.

According to a first aspect of the invention, provide a kind of being applicable to by fastening piece to be fixed on combustion engine cylinder head on the cylinder body, this cylinder head comprises the firing chamber; Control suction port and the relief opening of opening and/or closing with suction valve and outlet valve respectively; Be used to pass the through hole of fastening piece; And when seeing the fitting surface of cylinder body and cylinder head from the bottom, being arranged in the cavity part between firing chamber and the through hole, itself and the line that is connected suction port or relief opening center and through hole center overlap.

According to a first aspect of the invention, when the periphery generation thermal expansion of suction port or relief opening, the fastening part that cylinder head is fixed on the cylinder body is alleviated by the cavity part the effect of contraction of thermal expansion, cavity wherein is partly when seeing bottom the fitting surface of cylinder body and cylinder head, be positioned at the contiguous position that overlaps with straight line around suction port or the relief opening, thus can so that suction port or relief opening along rectilinear direction generation thermal expansion.Thus, cylinder head tightens part and comes the suction port that thermal expansion constraint is caused or the distortion of relief opening just can be avoided.In addition, around suction port or relief opening, concentrate and also be lowered, be the state of circle substantially thereby suction port or relief opening still can be kept after around it thermal expansion taking place with passing suction port or relief opening center and the basic thermal stress that overlaps the zone with the straight line of said straight line quadrature, caused by the thermal expansion constraint.

The result is even around suction port or the relief opening thermal expansion has taken place, by being arranged in this simple structure of cavity part on the cylinder head, just can guarantee that suction valve or outlet valve have had good sealing characteristics.This has just been avoided, and unburned combustion-gas mixture leaks in the suction port in the compression stroke process, thereby can effectively keep the accurate control to the combustion gas ratio.In addition, similarly, said structure can prevent in the compression stroke process that also unburned combustion-gas mixture from leaking in the relief opening, thereby can improve gas exhausting property.In addition, because the cavity part can allow to take place thermal expansion, thereby can adopt higher combustion temperature, thereby can keep higher power output.And the problem that cylinder head strengthens needn't appear, therefore the layout for internal-combustion engine can not produce any restriction.

According to a second aspect of the invention, since to cylinder body tighten the part the thermal expansion effect of contraction remission effect in the straight line both sides about equally, therefore the thermal expansion around suction port or the relief opening can be more even, and the shape of suction port or relief opening just can closer keep circular like this.The result is, except the advantage that a first aspect of the present invention had, but also can guarantee that suction valve or outlet valve have better sealability, thereby better keeps the accurate control of combustion gas ratio and further improve gas exhausting property.

According to a third aspect of the invention we, provide a kind of cylinder head of internal-combustion engine, it has the characteristics of the present invention first and second aspects, and wherein this cavity has partly constituted the cooling channel.

According to a third aspect of the invention we, cylinder head tightens the thermal expansion constraint that partly causes and can alleviate by the cooling channel that partly is made of cavity, simultaneously, can cool off by the freezing mixture that flows through the cavity part around suction port or the relief opening, thereby can reduce the thermal expansion of suction port or relief opening itself.Therefore, concentrate, and then can closer keep suction port or relief opening around it, before thermal expansion, to be circular state substantially owing to can further eliminate the distortion and the thermal stress of suction port or relief opening.

The result, except the advantage that first and second aspects of the present invention are had, by partly constitute this simple structure in cooling channel by cavity, can also guarantee that suction valve or outlet valve have better sealability, thereby keep the accurate control of combustion gas ratio better and further improve exhaust gas discharging.

Fig. 1 is the planimetric map of first embodiment of the invention being done from the fitting surface of combustion engine cylinder head;

Fig. 2 is the sectional view along the II among Fig. 1-the II line is done;

Fig. 3 is the sectional view along the III among Fig. 1-the III line is done;

Fig. 4 is the sectional view along the IV among Fig. 1-the IV line is done;

Fig. 5 is corresponding with Fig. 4, but expression is the second embodiment of the present invention;

Fig. 6 is corresponding to Fig. 4, expression be the third embodiment of the present invention;

Fig. 7 is an indicative view, has represented to produce suction port, the relief opening peripheral part of thermal stress.

Describe below with reference to Fig. 1 to the 5 couple of given embodiment of the present invention.

In first embodiment, described internal-combustion engine is a kind of V-type 6 cylinder spark ignition type SOHC water-cooled internal combustion engines that are provided on the automobile.This internal-combustion engine comprises an aluminium alloy cylinder and a pair of cylinder cap, and cylinder body wherein comprises the cylinder lateral body (bank) that a pair of V-arrangement is arranged, a pair of cylinder cap is separately fixed on each lateral body of cylinder body.What Fig. 1 showed is the fitting surface 2 of the cylinder head 1 of one of lateral body, and it matches with the cylinder body (not shown).Attention only describes cylinder body and the cylinder head on certain in a pair of lateral body in following explanation, and the cylinder body on another lateral body and the structure of cylinder head are essentially identical.

Each lateral body of cylinder body all has three cylinder portion of arranging along the axial direction of bent axle, bent axle wherein is supported on the cylinder body rotationally, and cylinder head 1 has the firing chamber of three single ramp types, it is recessed in the cylinder head 1, and be arranged on the crankshaft direction and (below will be called " arranged direction "), thereby relative with the cylinder-bore in the cylinder portion respectively, piston is to-and-fro motion in cylinder-bore.

Fig. 2 and Fig. 3 combined see, in each firing chamber, made and be

circular suction port

4a, 5a and basic relief opening 6a, 7a substantially for circle,

suction port

4a, 5a are the opening ends of a pair of intake duct 4,53 one sides in the firing chamber on the cylinder head 1, and control out and/or close by a pair of suction valve 8, the opening end of 3 one sides in the firing chamber of a pair of exhaust passage 6,7 on relief opening 6a, the 7a cylinder head 1 is opened and/or is closed by a pair of outlet valve 9 controls.

The center line A of suction valve 8 relative cylinder barrels is to gas-entered

passageway

4,5 lopsidedness, and same relatively center line A of outlet valve 9 is to exhaust passage 6,7 lopsidedness, they are opened and/or close by the control of a valve spare system, valve gear comprises a camshaft (not shown) and the rocking arm that is waved by the cam on the camshaft in the supported hole 12 that is supported on rotationally on the cylinder head 1, and suction valve 8 and outlet valve 9 are slidably mounted in being press-fitted in the conduit 10,11 in the cylinder head 1 respectively.This valve gear is arranged in valve cage, and valve cage is to become by the cylinder head cap seal that is fastened on the cylinder head 1.In addition, valve seat 13,14 press fit over respectively among

suction port

4a, 5a and relief opening 6a, the 7a, is used to make suction valve 8 and outlet valve 9 to take a seat thereon.

On the combustion chamber wall surface of each firing chamber 3,

suction port

4a, 5a be along the arranged direction setting, and near the center of the V-arrangement that is made of two lateral bodys, and relief opening 6a, 7a arrange along arranged direction, and near the lateral section of V-arrangement.And, on the middle position that is centered on by suction valve 8 and outlet valve 9 on the combustion chamber wall surface, be furnished with the opening 15a of a spark plug mounting hole 15.This mounting hole 15 is located substantially on the centre of two outlet valves 9, and its center line tilts to exhaust passage 6,7 with respect to the center line A of cylinder barrel (referring to Fig. 3).

Thereby be arranged on the cylinder head 1 is coolant jackets 19 of a cylinder head side around each firing chamber 3, it is connected with the coolant jacket of the cylinder body side of arranging on the cylinder body, freezing mixture passes through a plurality of connecting passages 16 under the pressure effect of coolant pump ..., 17,18,17 ', 18 ' be transported in the coolant jacket, freezing mixture just can flow into the coolant jacket of cylinder head side from the coolant jacket of cylinder body side like this.

These form the connecting passage 16 of cooling duct system ..., 17,18,17 ', 18 ' constitute by the more radially outer through holes of the center line A of relative combustion chamber 3, these through holes and with the circumferential arrangement of certain spacer ring firing chamber 3, and each connecting passage 16 ..., an end of 17,18,17 ', 18 ' formed the opening 16a on cylinder head 1 fitting surface 2 ..., 17a, 18a, 17 ' a, 18 ' a, the opening of the other end is then opened the coolant jacket 19 to cylinder head one side.In addition, each connecting passage 16 ..., 17,18,17 ', 18 ' all extend along center line A, and be parallel on most of planes of fitting surface 2 each connecting passage 16 ..., 17,18,17 ', 18 ' cross section and shape all substantially with opening 16a ..., 17a, 18a, 17 ' a, 18 ' a identical.Thereby, each connecting passage 16 ..., 17,18,17 ', 18 ' opening 16a ..., 17a, 18a, 17 ' a, 18 ' a be in the face of the cooling channel in the packing ring between cylinder body and the cylinder head 1, thereby make freezing mixture to flow into from the coolant jacket of cylinder body side the coolant jacket 19 of cylinder head side.In addition, these openings 16a ..., 17a, 18a, 17 ' a, 18 ' a be arranged on the fitting surface 2 in the scope of the endless belt part 20 (representing with double dot dash line among the figure) that has certain width around center line A, in the radial direction.

The coolant jacket 19 of cylinder head side comprises 3 annular cooling channel 19a, its connecting passage 16 round the firing chamber in a circumferential direction ..., 17,18,17 ', 18 ' opening is towards this passage, coolant jacket 19 also comprises one at the cooling channel 19b that extends on the arranged direction between gas-entered

passageway

4,5 and the exhaust passage 6,7, and cooling channel 19a, 19b connect mutually.

On the other hand, radial outside in endless belt part 20, arranged and be used for cylinder head is fixed on the through hole 21 to 28 of the clamping bolt (not shown) on the cylinder body, and be arranged in firing chamber 3 one sides, on arranged direction, gas-entered

passageway

4,5 one sides are provided with 4 through holes, and 6,7 one sides are furnished with other 4 in the exhaust passage.

Among these through holes 21 to 28, when when fitting surface 2 bottoms are seen, for each firing chamber 3, the center C 5 to C8 of the through hole 25 to 28 of 6,7 one sides lays respectively at substantially and connects cylinder barrel center C 1 and relief opening 6a, 7a center C 2 in the exhaust passage, on straight line L1, the L2 of C3.In addition, among these through holes 21 to 28, center C 6, the C7 of the through

hole

26,27 between the adjacent firing chamber 3 lays respectively at the intersection point of straight line L1, L2, straight line L1, L2 wherein passes the center of center C 2, C3 and adjacent firing chamber 3 relief opening 7a, the 6a of relief opening 6a, 7a respectively, one of them relief opening is near a relief opening on the adjacent firing chamber 3 of another firing chamber, and another relief opening is near a relief opening on another firing chamber of adjacent firing chamber 3.

In addition, the through hole 21 to 24 of gas-entered

passageway

4,5 one sides is arranged on respect to straight line and keeps substantially on some location points of linear symmetric on the fitting surface 2, and straight line wherein is the straight line that fitting surface plane, 2 place and straight line A place Plane intersects form.Herein, when when fitting surface 2 bottoms are seen, our supposition is for each firing chamber 3, with through

hole

21,22 center C 11, C12; Through

hole

22,23 center C 12, C13; Through

hole

22,23 center C 12, C13; And the straight line that

suction port

4a, 5a center C 9, the C10 of through

hole

23,24 center C 13, C14 and each firing chamber 3 couple together is respectively L3, L4.Like this, through

hole

22,23 center C 12 between the adjacent firing chamber 3, C13 lay respectively on the intersection point of two groups of straight line L3, L4, straight line L3, L4 pass through the suction port 5a of center C 9, C10 and the adjacent firing chamber 3 of

suction port

4a, 5a, the center of 4a respectively, one of them suction port is the suction port near an adjacent firing chamber 3 of another firing chamber, and another suction port is a suction port near another firing chamber 3 of adjacent firing chamber 3.

In addition, in the through hole 21 to 24 of gas-entered

passageway

4,5 one sides, two through

holes

21,24 that are positioned on the cylinder head 1 fitting surface 2 arranged direction ends still are used for carrying lubricant oil, the passage so that valve gear is lubricated simultaneously.And, among the through hole 25 to 28 of exhaust passage 6,7 one sides, be positioned at cylinder head 1 fitting surface 2 ends two through

holes

25,28 simultaneously still with the through hole of the coaxial mounted cylinder locating stud of clamping bolt periphery.Notice that what reference character 29 was represented is two air vents, what reference character 30 was represented is four lubricant oil return flow lines.

For each firing chamber 3 as shown in figs. 1 and 4, two connecting

passages

17,18 of exhaust passage 6,7 one sides and two connecting passages 17 ', 18 ' of gas-entered

passageway

4,5 one sides have constituted the cavity part in the cylinder head 1, and, when when fitting surface 2 bottoms are seen, these cavitys part is between the through hole 25 to 28 of firing chamber 3 and relief opening one side, and between firing chamber 3 and gas-entered

passageway

4,5 one sides, overlapping on the location point of four straight line L1, L2, L3, L4 respectively.Straight line L1, L2, L3, L4 are respectively by M1, M2, M3, M4 point, these points are respectively the central position of connecting

passage

17,18,17 ', 18 ' on width direction, width direction wherein and straight line L1, L2, L3, L4 vertical (below will be called " orthogonal direction ").

In this first embodiment, connecting

passage

17,18,17 ', 18 ' comprises the cross-sectional width of

opening

17a, 18a, 17 ' a, 18 ' a on orthogonal direction the internal diameter than relief opening 6a, 7a and

suction port

4a, 5a is slightly little respectively, and its width is to have considered the thermal expansion that relief opening 6a, 7a and

suction port

4a, 5a allowed and fixed, wait a moment and will make an explanation this, thus the distortion that elimination relief opening 6a, 7a and

suction port

4a, 5a are caused by thermal expansion.Similarly, the cross-sectional width of connecting

passage

17,18,17 ', 18 ' on each bar straight line L1, L2, L3, L4 direction also suitably determined according to same structural consideration.Given this, on the area that connecting

passage

17,18,17 ', 18 ' opening 17a, 18a, 17 ' a, 18 ' a may occur and shape and the connecting passage except that opening 17a, 18a, 17 ' a, 18 ' a the different situation of other parts.

Working principle and advantage according to the first embodiment of the invention of foregoing description manufacturing will be described below.

Owing to be subjected to the heating of gas mixture burning in the firing chamber 3, and be raised to very high temperature around relief opening 6a, the 7a of cylinder head 1 and suction port 4a, the 5a, and then thermal expansion becomes big.When this situation of generation, owing to overlapping straight line L1, L2, L3, the location point place of L4 is by connecting

passage

17,18,17 ', 18 ' has formed the cavity part, the thermal expansion constraint that is produced by cylinder head 1 fastening part just is deflated a mouthful 6a, 7a and suction port 4a, connecting passage 17 around the 5a, 18,17 ', 18 ' has alleviated, especially overlapping straight line L1, L2, L3, the neighbouring part of L4, make thus along straight line L1, L2, L3, the thermal expansion of L4 direction has become possible, straight line L1 wherein, L2, L3, L4 is with relief opening 6a, 7a and suction port 4a, the center of the center of 5a and through hole 25 to 28 and through hole 21 to 24 couples together, and by clamping bolt cylinder head 1 is fixed on the cylinder body in fastening part.

This has not only been avoided the relief opening 6a, the 7a that the inhibition of thermal expansion are caused owing to cylinder head 1 fastening part and the distortion of

suction port

4a, 5a, and certain zone is concentrated by the thermal stress that thermal expansion causes around having reduced relief opening 6a, 7a and

suction port

4a, 5a, this area coincidence center C 2, C3, C9, the C10 by relief opening 6a, 7a and

suction port

4a, 5a, and with straight line L1, L2, L3, L4 at right angles intersects basically, thereby the shape that has kept relief opening 6a, 7a and

suction port

4a, 5a, they were essentially circular before thermal expansion takes place.

The result is, by adopting on cylinder head 1 with connecting

passage

17,18,17 ', 18 ' simple designs as the cavity part, can make outlet valve 9 and suction valve 8 have good airtight divinatory symbol performance, even be subjected under the situation of thermal expansion in the combustion chamber wall surface that comprises relief opening 6a, 7a and

suction port

4a, 5a peripheral part.So just prevented that unburned oil-gas mixture leaks in suction port and the relief opening in compression stroke, thereby can guarantee accurate control and raising gas exhausting property the combustion gas ratio.And because connecting

passage

17,18,17 ', 18 ' can expand in certain degree, the maximum combustion temperature of burning can have certain rising, thereby can realize higher power output.In addition, because cylinder head 1 needn't strengthen, thereby just can not produce any restriction for the topology layout of internal-combustion engine.And, because can be because of the weight of the increasing increasing combustion engine of cylinder head 1, so can not worsen fuel efficiency.

And, since when as aforesaid when fitting surface 2 bottoms are seen, width central point M1 on orthogonal direction of

opening

17a, 18a, 17 ' a, 18 ' a, M2, M3, M4 are in occupation of the position that overlaps straight line L1, L2, L3, L4, cylinder head 1 fastening part equates basically to the alleviation degree that is suppressed at straight line L1, L2, L3, L4 both sides of thermal expansion, the thermal expansion of the combustion chamber wall surface around relief opening 6a, 7a and suction port 4a, the 5a will be more even like this, is circular substantially thereby can keep the shape of relief opening 6a, 7a and suction port 4a, 5a.The result is, can guarantee that suction valve 8 or outlet valve 9 have better sealability, thereby better guarantees the accurate control of combustion gas ratio and further improve gas exhausting property.

In addition, because connecting

passage

17,18,17 ', 18 ' also is the cooling channel simultaneously, the thermal expansion of fastening part constraint not only can be passed through connecting passage 17 like this, 18,17 ', 18 ' eliminates, but also can eliminate by whole firing chamber 3 walls, particularly by flowing through connecting

passage

17,18,17 ', 18 ' freezing mixture can be to relief opening 6a, 7a and suction port 4a, cool off around the 5a, thereby whole firing chamber 3 walls, especially relief opening 6a, 7a and suction port 4a, thermal expansion around the 5a just has been lowered, and then further avoided relief opening 6a, 7a and suction port 4a, the distortion of 5a, also contained simultaneously because the inhibition of thermal expansion is concentrated in the thermal stress that these opening neighbouring parts produce, so just made relief opening 6a, 7a and

suction port

4a, 5a can Bao Te they before thermal expansion takes place, be essentially circular shape and become possibility.

In addition, though the burning sintering on the cylinder head 1 around the spark plug mounting hole 15 also with relief opening 6a, 7a and suction port 4a, equally be heated to very high temperature around the 5a, but when when fitting surface 2 bottoms are seen, because the center C 4 of spark plug mounting hole 15 is positioned at straight line L1, L2, L3, near the L4, at straight line L1, L2, L3, thermal expansion can be passed through connecting passage 17 to the influence of spark plug mounting hole 15 peripheries on the L4 direction, 18,17 ', 18 ' and eliminate, so, relief opening 6a, 7a and suction port 4a, the distortion that 5a is caused by thermal expansion around the mounting hole 15 just can be suppressed.

To be described the improvement part among the improved embodiment of first embodiment's part one below.

In first embodiment, when as aforementioned when fitting surface 2 bottoms are seen, with the straight line L1, the L2 that are connected relief opening 6a, 7a center C 2, C3 and through hole 25 to 28 center C 5 to C8, and connect the straight line L3 of

suction port

4a, 5a center C 9, C10 and through hole 21 to 24 center C 11 to C14, position layout that L4 coincides, be used to absorb whole combustion chamber wall surface one especially the cavity of relief opening 6a, 7a and the peripheral position thermal expansion of

suction port

4a, 5a partly be connecting

passage

17,18,17 ', 18 ', these passages are that the through hole by cooling liquid flowing channel constitutes.In a second embodiment, as shown in Figure 5, cavity partly is provided between firing chamber 3 and the through hole 25 to 28 and between firing chamber 3 and through hole 21 to 24 and the recess part 40 of going to the bottom have opening 40a on fitting surface 2.In this case, also be disposed on the position that overlaps with straight line L1, L2, L3, L4 at recess part on the orthogonal direction 40.Thereby, with connecting

passage

17,18,17 ', 18 ' design is the same, according to the whole wall one in firing chamber especially relief opening 6a, 7a and suction port 4a, the situation of the thermal expansion that is allowed around the 5a is set out, the cross section of recess part 40 is at straight line L1, L2, L3, on the L4 direction and the width on orthogonal direction, the degree of depth on the plane of the fitting surface 2 that is parallel to opening 40a place, area and shape can suitably be determined, so just can eliminate distortion, especially the relief opening 6a of whole combustion chamber wall surface, 7a and suction port 4a, the distortion that causes by thermal expansion around the 5a.

In first embodiment be the

connecting passage

17,18,17 ', 18 ' that is used as the cooling channel tell on and advantage beyond, except this point difference, second embodiment can provide effect performance and the advantage identical with first embodiment.

In addition, though in a second embodiment, recess part 40 is positioned at endless belt part 20 zones on straight line L1, L2, L3, L4 direction, and they also can be in any position between through hole 21 to 28 and the firing chamber 3.For example, recess part 40 can be disposed in the P1 and the P2 position of double dot dash line indication shown in Figure 5.In addition, the form that recess part 40 can also adopt a plurality of recess partes 40 to arrange at certain intervals along straight line L1, L2, L3, L4 so just can increase the thermal expansion that is allowed by a plurality of recess partes 40.In addition, in other embodiment of the cavity part that is made of recess part, the opening of recess part can be positioned at any position, and not necessarily is positioned on the fitting surface 2.

When as aforementioned when fitting surface 2 bottoms are seen, though in first embodiment, the

connecting passage

17,18,17 ', 18 ' that overlaps with straight line L1, L2, L3, L4 is positioned at endless belt part 20, but connecting

passage

17,18,17 ', 18 ' also can be in any position between firing chamber 3 and through hole 21 to 28 on straight line L1, L2, L3, the L4 direction.And the recess part that constitutes a cooling channel part can be used as

cooling channel

17,18,17 ', 18 ', rather than as the connecting passage that constitutes by through hole, and can assign to constitute the cavity part that allows thermal expansion by recess.In addition, the opening of recess part can be formed on the fitting surface 2, perhaps faces toward any position except that fitting surface 2 of cooling channel opening.A kind of example in back 6 describes with reference to the accompanying drawings as the 3rd embodiment.

In the 3rd embodiment shown in Figure 6, recess part 41 is arranged in connecting passage among

first embodiment

17,18,17 ', 18 ' same position place, and has towards the opening 41a around the annular cooling channel 19a of firing chamber 3.In the 3rd embodiment, thickness t between recess part 41 bottom 41b and the fitting surface 2 is less than the thickness t 0 between cooling channel 19a and the position of fitting surface 2 except that forming recess part 41 parts, and recess part 41 bottom surfaces have just become the bottom surface of very thin cooling channel 19a like this.Given this, the rigidity of cooling channel 19a on straight line L1, L2, L3, L4 direction owing to be provided with thin recess part 41 less than the rigidity of recess part 41 other parts, therefore, the same with first embodiment, present embodiment also can obtain to eliminate the effect of cylinder head 1 fastening part thermal expansion constraint, and effect performance and the advantage the same with first embodiment is provided equally.

Though in previous embodiment, when fitting surface 2 bottoms are seen, connecting

passage

17,18,17 ', 18 ' or the width center of recess part on orthogonal direction in occupation of with straight line L1, L2, L3, the position that L4 overlaps, as long as at connecting

passage

17,18,17 ', 18 ' or recess part be positioned at and straight line L1, L2, L3, L4 overlaps under the prerequisite of position, connecting

passage

17,18,17 ', 18 ' or the width center of recess part on orthogonal direction might not be positioned at and straight line L1, L2, L3, the position that L4 overlaps, concrete position can considered the thermal expansion constraint of whole combustion chamber wall surface, relief opening 6a particularly, 7a and suction port 4a, thermal expansion owing to whole combustion chamber wall surface around the 5a causes under the situation of the constraint of expanding, suitably determine, particularly by connecting passage 17 is set, 18,17 ', 18 ' or recess assign to improve relief opening 6a, 7a and suction port 4a, position around the 5a.In addition, cross sectional area and the shape that has connecting

passage

17,18,17 ', 18 ' shape of cross section and the area of opening 17a, 18a, 17 ' a, 18 ' a or have a recess part of opening can arbitrarily be set.

In addition, the cavity part can be made of the space that communicates with ambient atmosphere, perhaps by being made of the space that closely completely cuts off by stopper and ambient air.In both of these case, in the space, can charge into other materials beyond fluid or the freezing mixture, so just can by permission relief opening 6a, 7a and

suction port

4a, 5a on every side and whole combustion chamber wall surface the distortion that relief opening 6a, 7a and

suction port

4a, 5a are eliminated in thermal expansion can take place.

In either case, suppose as above-mentioned when fitting surface 2 bottoms are seen, as long as partly being positioned at straight line L1, L2, L3, L4, cavity overlaps under the situation of position, the cavity part that is arranged between firing chamber 3 and the through hole 21 to 28 can adopt any form, and, cavity partly formed low rigidity section by being set, thereby, particularly allow relief opening 6a, 7a and suction port 4a, the thermal expansion of 5a peripheral part to alleviate the thermal expansion constraint of cylinder head 1 fastening part just by allowing whole combustion chamber wall surface generation thermal expansion.

Though for each embodiment, all be provided with two suction valves 8 and two outlet valves 9 in each firing chamber 3, the number of suction valve and outlet valve is not limited to above-mentioned number.

Although just specifically described certain embodiments of the invention in this article, clearly, the present invention can make a lot of improvement under the prerequisite that does not break away from its core concept.

Claims

1, a kind of cylinder head of internal-combustion engine, this cylinder head adopt fastening piece to be fixed on the cylinder body, and described cylinder head comprises:

At least one firing chamber;

At least one suction port and at least one relief opening, it is respectively by the suction valve and the outlet valve control switch of correspondence;

The through hole that described fastening piece is passed through; And

At least one is arranged in the cavity part between described firing chamber and the described through hole, when seeing the fitting surface of described cylinder head and described cylinder body from the bottom, this cavity partly is positioned at and the position that overlaps straight line that is formed by connecting by described suction port or described relief opening center and described through hole center.

2, the cylinder head of internal-combustion engine as claimed in claim 1 is characterized in that, described cavity part is being positioned at the position that overlaps with described straight line in itself perpendicular to the part of the transverse center on the described rectilinear direction.

3, the cylinder head of internal-combustion engine as claimed in claim 1 is characterized in that, described cavity has partly constituted cooling passage.

4, the cylinder head of internal-combustion engine as claimed in claim 1 is characterized in that, described cavity partly is disposed in the ring belt area around described firing chamber on the fitting surface, and this cavity part radially has a predetermined width in described firing chamber.

5, the cylinder head of internal-combustion engine as claimed in claim 1 is characterized in that, described cavity part has opening to the fitting surface of described cylinder head.